Well treatment fluids are circulated through wellbores and pumped through wellbores into subterranean formations in a variety of different applications. Examples of well treatment fluids include drilling fluids and stimulation fluids. An example of a stimulation fluid is a fracturing fluid that is pumped through a wellbore into a subterranean formation penetrated by the wellbore to create or enhance one or more fractures in the formation in order to increase the conductivity of the formation and allow hydrocarbons to more easily flow from the formation to the wellbore.
Particulate material is used in well treatment fluids for various purposes. For example, particulates are often used as a fluid loss control agent to fill and seal pore spaces in a subterranean formation. As another example, particulates are often added to a well treatment fluid to divert the fluid toward a desired area within a formation. For example, it may be desirable to add a diverting agent toward the end of a treatment operation being carried out on a particular section of a formation in order to slow or stop the flow of further treatment fluid into that section, thereby diverting the treatment fluid to another area of the formation.
Particulates made of degradable material are especially useful in well treatment fluids because of the ease associated with their clean up. However, they can be problematic in that they are difficult to grind into the small sizes often necessary to prevent fluid loss and carry out other functions. For example, degradable particulate materials based on polylactic acid (“PLA”) often require cryogenic grinding to achieve the small sizes needed to seal pore spaces and fractures. Also, degradable particulate materials formed of plastic or polymer materials may not have a mechanical strength sufficient for all applications.